I have resolved to demonstrate by a certain and undoubted course of argument, or to deduce from the very condition of human nature, not what is new and unheard of, but only such things as agree best with practice.
Baruch SpinozaSince love of God is the highest felicity and happiness of man, his final end and the aim of all his actions, it follows that he alone observes the divine law who is concerned to love God not from fear of punishment nor love of something else, such as pleasure, fame, ect., but from the single fact that he knows God, or that he knows that the knowledge and love of God is the highest good
Baruch Spinoza